It is an ongoing challenge to enhance the data rate in a mobile communication network. This may be pursued by developing completely new systems. An example of this type of evolution is the change in network architectures from a Global System for Mobile Communications (GSM) to a Universal Mobile Telecommunications System (UMTS) applying Wideband Code Division Multiple Access (WCDMA) and further to Long Term Evolution (LTE). Alternatively, the increase of the data rate may be obtained by developing the existing architectures. For example, a general packet radio service (GPRS) and enhanced data rates for global evolution (EDGE) were developed on top of the existing GSM network. Further, high-speed downlink packet access (HSDPA) was developed to coexist with the UMTS network.
One possible way to increase the data rate is to enable the dual channel reception in the mobile communication network. This technique is called a dual cell (DC) HSDPA. According to possible solutions for DC-HSDPA, a mobile terminal would require two separate receivers. Both of the receivers could separate the in-phase (I) and the quadrature (Q) branch from the received signal. The use of two receivers is, however, a highly space- and money-consuming solution. Alternatively, a diversity receiver of the mobile terminal could be applied together with the original receiver (such as a direct conversion receiver) for receiving two data channels simultaneously.